Jar device for pumps



March l0, 1959 D. Q. HooKs JAR DEVICE FOR PUMPS Filed July 22, 1955 2 Sheets-Sheet 1 INVENTOR. QON/JLD Q. HOOL/S.

March 10, 1959 Y D. Q. HooKs JAR DEVICE FOR PUMPS 2 Sheets-Sheet 2 Filed July 22, 1955 INVENTOIL 00A/ALU Q. Hoces,

United States Patent O 2,876,993 JAR DEVICE FOR PUMPS Donald Q. Hooks, Henderson, Tex. Application July 22, 1955, Serial No. 523,793 2 Claims. (Cl. 255-27) This invention relates to jar devices for pumps.

An object of the invention is to provide a jar device for disengaging a pump when it becomes stuck in a well, the device forming a permanent part of the pumps structure and becoming operative only upon the sticking of the pump.

Another object of the invention is to provide a jar 'device for a pump which, with the sucker rod, may be readily disengaged from the plunger of the pump in the event jarring operations are not elective to loosen the plunger and the pump must be stripped.

Other objects and advantages of the invention will appear from the following description considered in conjunction with the attached drawings in which:

Figure 1 is a longitudinal cross sectional view of the device of the present invention installed in a well pump and occupying its normal position;

Figure 2 is a longitudinal cross sectional view of the assembly of Figure l with the device of the present invention in its jarring position;

Figure 3 is a view taken along the line ure 1;

. Figure 4 is a longitudinal cross sectional view of another form of the device of the present invention installed in a well pump and occupying its normal position;

Figure 5 is an exploded view of the elements comprising the device of Figure 4, except the cylinder',

Figure 6 is a longitudinal view of the cylinder of the device of the form of Figure 4.

Referring to Figures 1 to 3 of the drawings, the reference numeral designates a well tubing in which is positioned a pump, generally designated 16, and a sucker rod 17, the sucker rod 17 being spaced above the pump 16 and carrying an adapter plug 18 upon its lower end. The device of the present invention, generally designated 20, is interposed between and connected to the plug 18 and the pump 16 and consists of the parts hereinafter described.

The outer element of the device 20 of the present invention consists of a hollow open ended cylinder 21 having one end connected to the plug 18 and having the other end constricted to form an internal shoulder 22. The said one end of the cylinder 21 is interiorly threaded and a reduced end portion 23 of the plug 18 is threaded therein to close the said end of the cylinder 21 and connect the cylinder 21 to the sucker rod 17. A transversely extending slot 24 is formed in the end portion 23 of the plug 18, as shown in Figure 1.

Within the cylinder,21 is a piston 26 normally positioned adjacent the plug 18. The piston 26 is slidable within the cylinder 21 from its normal position to a position of striking contact with the shoulder 22, as shown in Figure 2. The piston 26 has a key 27 formed thereon which conformably ts into the slot 24 of the plug 18 when the piston 26 is in its normal position.

Extending slidably through the constricted end of the cylinder 21 is a piston rod 28 which has one end con- 3-3 of Fign '2,876,993 Patented Mar. 10, 195,9:

nected to the piston 26 and has the other end secured to the pump 16. As indicated in Figure l, the other end of the piston rod 28 is connected to the pump 16 by being threaded into a coupling 29, the coupling being secured to the pump 16 by means of a pony rod '40.

Extending transversely through the cylinder 21 and the piston 26, is a shear pin 31 for releasably holding the piston 26 in its normal position. The portion inwardly of and adjacent the one end of the cylinder 21, adjacent the plug 18, is reduced in external diameter to form an exterior shoulder 32 upon the cylinder 21 adjacent the end closed by the plug 18. A sleeve 33 surrounds the reduced end portion of the cylinder21 and is slidable longitudinally thereon between the shoulder 32 and an outwardly extending ange 34 on the plug 18 which abuts the associated end of the cylinder 21 when the plug 18 is in closing relation therewith, the sleeve 33 normally resting upon the shoulder 32 when the device of the present invention is in its upright position within the tubing 15. The sleeve 33 is provided with a pair of diametrically opposed apertures 36, conformably shaped to receive the pin 31 and arranged so that when the sleeve 33 is in its normal position uponthe shoulder 32, the apertures 36 are nearer the shoulder 32 than the pin 31 and, thus, are out of registry with the pin 31, the sleeve 33, in this position, serving to hold the pin 31 in place in the cylinder 21 and the piston 26. At the same time, the sleeve 33 may be moved toward ange 34 of f the plug 18 and rotated about the cylinder 21 so as to bring the apertures 36 into registry with the pin 31.

When inserted into a pump mechanism, the device of the present invention is placed in its normal position, as shown in Figure l, with the shear pin 31 holding the piston 26 in abutting engagement against the end portion 23 of the plug 18 and the device remains in this position throughout the normal operation of the pump. However, should the pump 16 become stuck in the tubing 15, h raising force is applied to the sucker rod 17 suflicient to shear the pin 31, without deforming any other part of the structure, and the device of the present invention comes into play As soon as the pin 31 is sheared, the piston 26 and the cylinder 21 are freed from each other for relative movement and the continued application of the raising force upon the sucker rod 17 causes the cylinder 21 to move upward sharply and bring the shoulder 22 into striking contact against the adjacent portion of the piston 26, the piston 26 having remained stationary within the tubing 15 because of its connection to the stuck pump 16. The shock of the blow delivered by the shoulder 22 upon the piston 26 will be transmitted through the piston rod 28 to the pump 16 and will, under normal circumstances, be sufficient to dislodge the pump 16. If the initial blow does not dislodge the pump 16, the sucker rod 17 may be raised and lowered in reciprocating movement to raise and lower the cylinder 21 and deliver successive blows to the piston 26. When the pump 16 has been dislodged, the cylinder 21 is raised above the top of the tubing 15, the sleeve 33 is moved to align the apertures 36 with the pin 31 and the used pin is removed and a new pin 31 inserted to hold the piston 26 in its normal position. The device is then ready for reuse.

A special feature of the device of the present invention adapts it to be disconnected from the pump 16 while still in the tubing, as may be necessary if the pump 16. dees all efforts to loosen it by the jarring method. To disconnect the device from the pump 16, the cylinder 21 is lowered until the piston 26 abuts the end portion 23 of the plug 18 and the key 27 is received within the slot 24. The piston 26 is thus rmly connected for rotation with the plug 18 and the sucker rod 17 and if the rod 17 ternal shoulder 32 is rotated in the proper direction, the piston rod '28 will be unscrewed from its connection with the coupling 29 and the sucker rod 17 and the device of the present invention may then be withdrawn from th'e tubing 15.

In the form of the device as shown in Figures 4 to 6, such form differs over the form of Figures l to 3 inclusive hereinabove described in only two specific aspects, the lrst one being in the connection of the piston 26 and the shear pin 31 to the cylnider 21 and the second one being, in the connection of the coupling 29 to the cylinder 21. Reverting to the lirst aspect, it will be apparent from Figures 4 to 6 inclusive that the upper end of the cylinder 21 is provided with an inand slidably received within the upper end of the cylinder 21 and normally resting upon the shoulder 32 is a sleeve 33. The sleeve 33' is provided with a pair of diametrically opposed apertures 36 which are conformably shaped to receive a shear pin 31'. The shear pin 31 extends through the transverse opening 26' formed in the piston 26 and is supported at its ends in the apertures 36'. By this arrangement, a Huid seal construction can be achieved at the top of the device, the seal being the contact of the llange 34 on the plug 18 with the top machined end of the cylinder 21. Also, the piston 26 and the sleeve 33' can be easily replaced if the shear pin holes 36' become damaged through repeated use, eliminating the replacement of the cylinder 21 and sleeve 33 as in the form of Figures 1 to 3. In addition, the shear value or size of the tool may be easily changed by simply inserting a piston rod 28 and matching sleeve 33' with a different size shear pin 31', enabling the simplilication of manufacture and assembly.

As for the second aspect, reference to Figures 4 to 6 inclusive will show that the lower end of the cylinder 21 is provided with a female tapered seat 21' in which is received a complemental male tapered seat 29' formed of the coupling on the one end of the coupling 29 which is connected to the other end of the piston rod 28 and on the other end of the cylinder for slidably and sealingly connecting the coupling 29 to the cylinder 21. These cooperating tapered seats 21' and 29' result in two important advantages, namely the wedging effect preventing the placing of a strain on the shear pin 31' which is holding the piston rod 28 in its fixed position, and forming a frictio lock which prevents the piston rod 28 from ming unscrewed 29" of the coupling 29 is screwed on the left-hand thread of the piston rod 28. In achieving the fluid tight seal between the cylinder 21 and the coupling 29 a longitudinal pull is applied to the piston rod 28 by the screw jack principle. This longitudinal pull is transmitted to the shear pin 31' which holds the piston 26 in a. xed position within the sleeve 33' resting upon the internal shoulder 32 within the cylinder 21. 0f course, this longitudinal pull to a minimum to prevent preloading of the shear pin 31' and destroy the predetermined shear value of the shear pin. The tapered 4 female seat 21' of the cylinder 21 and the tapered male seat 29' of the coupling 29 wedge together where the coupling 29 is screwed on the threaded end of the piston rod 28 to form a friction lock which prevents the two parts from being accidently unscrewed in the well during pumping operation. After the shear pin 31' has been sheared, the cylinder 21 and the coupling 29 are no longer in wedged contact, and so, these parts can be easily separated from each other by revolving the from the coupling 29.

This application is a continuation-impart of my prior application Serial No. 446,839, tiled July 20, 1954, now abandoned.

Having thus described the invention what is new and desired to be secured by Letters Patent is:

l. A jar device comprising a hollow open ended cylinder having one end adapted to be connected to a sucker rod adapter plug, said cylinder having the portion adjacent the other end constricted to form an internal shoulder, a piston within said cylinder and normally adjacent said plug, said piston being slidable within said cylinder from its normal position to a position of striking contact with said shoulder, a piston rod extending slidably through the constricted portion of said cylinder and having one end secured to said piston, a coupling having one end detachably connected to the other end of said piston rod and having the other end adapted to be connected to a pump, the portion of the cylinder inwardly of and adjacent said one end of said cylinder being provided with an internal shoulder, a sleeve resting upon said last named shoulder and slidable between the latter shoulder and said plug, and a shear pin extending transversely through said piston and said sleeve for releasably holding said piston in its normal position.

2. A jar device able between the latter shoulder and said plug, and a shear pin extending transversely through said piston and said sleeve for releasably holding said piston in its normal position.

References Cited in the file of this patent UNITED STATES PATENTS 

